code: def _map_into_single_column(matrix):
      if len(np.array(matrix).shape) == 1:
          return np.array(matrix)
  
      return _merge_columns(matrix)
  
file_path: fairlearn/test/unit/input_convertors.py
imports: import numpy
  import pandas
  from fairlearn.utils._input_validation import _merge_columns
label_desc: Use image node_id 7 for calling a global function with example usage: _map_into_single_column(matrix) and returns: _merge_columns, np